The BADERC Transgenic Core is located at the Beth Israel Deaconess Medical Center (BIDMC). The Core performs embryo microinjection services; specifically, microinjection of investigator-derived transgenic DNA constructs, for the purpose of making transgenic mice, and also microinjection of investigator-derived targeted embryonic stem cells (ES cells), for the purpose of making gene knockout mice or gene knockin mice (i.e. loxed alleles, point mutations, etc.). In the last 5 year cycle of this grant (2004-2009), the BADERC Transgenic Core provided timely, cost-effective services. In total, 92 projects were performed (injection of DNA transgenes - 49 projects, injection of targeted ES cell clones - 40 projects, cyropreservation of mutant embryos - 3 projects). This level of services represents a 84% increase in activity over the previous 5 year cycle of this grant (1999-2004). These services were provided to 15 different BADERC investigators from 4 different institutions. During this period, BADERC investigators published 43 papers that involved the utilization of genetically altered mice generated by the BIDMC Transgenic Facility. In addition, BADERC investigators obtained 22 NIH-based grants that involved the generation of genetically engineered mice. In summary, the Transgenic Core has provided extensive, cost-effective services to a wide array of productive BADERC investigators.